Severe wound infection following arthroplasty is an extremely serious complication which not only endangers the success of the operation, but also results in chronic osteomyelitis preventing further attempted surgical reconstruction. The overall objective of the proposed research is to study in vitro and in vivo aspects of incorporation of prophylactic antibiotics into methyl methacrylate cement used in arthroplastic surgery. Specifically, the studies are designed to: a. Evaluate separately and in combination, the most appropriate concentrations of gentamicin and cephalothin to incorporate in the cement. b. Determine the pharmacokinetics governing release of antibiotics from the cement. c. Determine the effect of admixed antibiotics upon physical, thermal, and fluid characteristics of the cement. A six-member interdisciplinary group representing the following areas has been formed: Orthopedic surgery, Dentistry, Pharmacy, Microbiology, and Engineering. The work has been divided into areas in an attempt to best utilize individual contributions from group members. A two-year program covering microbiological, physiological, and physical aspects of adding antibiotics to Surgical Simplex P(R) bone cement is described.